Inductively coupled plasma (ICP) is a high temperature source that is used for converting samples of substances in to a form that can be analyzed by various types of spectrometers. These spectrometers include mass spectrometers, atomic and optical emission spectrometers and other instruments used for both qualitative and quantitative analysis. The samples are typically comprised of substances dissolved in solution; a suspension of substances in a liquid; or solid substances carried within a gas flow.
In an ICP torch, the plasma is generated when a flow of gas, such as argon, is ionized in an intense electromagnetic field. When an optimal plasma temperature and energy density is generated, a sample that is introduced through the torch into the plasma can be vaporized, atomized, ionized, and/or excited prior to elemental analysis.
Generally, the conditions to achieve an optimal plasma temperature and energy density are reflected by the argon gas flow rate and the power intensity of the electromagnetic field. In most conventional ICP systems, the operation of the plasma torches required a significantly high argon gas flow, in excess of 16 liters per minute (I/m), and a radio frequency (RF) power in excess of 1 kW, typically between 1400 W and 1600 W, in order to generate a suitable electromagnetic field. As a consequence, the regular use of these ICP systems under these conditions can result in a significant operating cost.